Air cooled furnace wall



June 1931- H. H. BAUMGARTNER 1,812,315

AIR COOLED FURNACE WALL Filed Sept. 16, 1926 5 Sheets-Sheet l H. H. BAUMGARTNER AIR COOLED FURNACE WALL June 30, 1931.

3 Sheets-Sheet 2 titty,

Filed Sept. 16, 1926 June 30, 1931. U ER 1,812,315

AIR COOLED FURNACE WALL Filed Sept. 16, 1926 3 Sheets-Sheet 3 Patented June 30, 1931 UNITED STATES PATENT OFFICE HENRY H. BA UMGARTNEB, OF BELLEVILLE, NEW JERSEY, ASSIGNOB TO DRAKE NON- CLINKERING FURNACE BLOCK COMPANY. INC., 0! NEW YORK, N. Y., A. CORPORA- TION OF NEW YORK AIR GOOLED FURNACE WALL I a eas filed September is, 1926. Serial No. 135,925.

This invention is a novel air cooled furnace wall, and has for its general objectto afford an improved air cooled wall adapted for modcm high service boiler furnaces, and one which will allow continuous operation with high efficiency, and which will be strong and durable and at the same time simple in structure, easy to install and involving the need of a small number of shapes of wall elements. A particular object is to afford a furnace wall which will have a long life and therefore less cost in the long run, due to the use of so-called super-refractory material, such as silicon carbide, a commercial form of which is known as carbo-glaze, or other analo ous refractory of superior quality, having high ability to withstand heat, high heat conducting power, and the ability to reject the attachment of clinkers. While such refractories are of relativel hi h first cost this is more thanovercome l iy the long durability, in connection with a mode of structure wherein the super-refractory is used only as a facing, at the inner or fire side of the Wall, the outer wall elements and intermediate ele-- ments consisting of clay refractories which may be of second grade and relatively low cost. A further object is to give a construction of air cooled wall such as to afford flexibility for expansion and contraction due to great variations of temperature, and the wall of this invention permits the exposed elements to adjust themselves or float in both vertical and horizontal directions. A further object is to provide a hollow furnace wall in which the face elements are positively air cooled without the necessity of admitting air through the elements into the furnace, although air admission apertures could been ployed without departing from the pr nc ples of the invention. The cooling air is caused to circulate vertically, or horizontally or a combination of these, or otherwise, be-- tween the inner or face elements or tiles of the wall and the outer or back elements, in a. manner to sweep or scrub the entire interior hot surfaces of the heat conducting refractory face elements, thus rapidly removing the heat and maintainin the wall relatively cool, the air thus heated sing available if desired for feeding into the furnace as air of combustion.

Further objects are to provide a wall wherein the face elements are interlocking, and yet largely self supporting, and may be small enough to absorb internal stresses under temperature changes; and wherein bulging, buckling and the like are prevented by 'a system of internal ties or links flexibly connecting the wall facing and backing, holding the facing in the plane of the wall, yet admitting of expanding movements in all directions in the plane of the wall. Because of the several described features furnace efficiency and service are enhanced due to the availability of increased temperatures of combustion without resulting harm to the combustion chamber walls. A further object is to afford facility of removal and renewal of individual wall face elements, and interior tie members or links, which may be impaired by heat or otherwise. Other and further objects and advantages will be explained in the following description of an illustrative embodiment of the invention, or will be apparent to those skilled in the subect.

To the attainment of the objects and advantages referred to the present invention consists in the novel air cooled furnace wall and the novel features of construction, operation, combination, arrangement, design and detail herein described or illustrated.

In the accompanying drawings Fig. 1 is a partial face or interior View of a furnace wall embed 'in the present invention, the same being ro ken' away horizontally to increase the scale of the drawing, and the wall facing being partially removed to show the interior structure.

Fig. 2 is a vertical section taken on the line 2-2 of Fig. 1 and looking from the right. Fig. 3 is a similar vertical section taken on the line 3-3 of Fig. 1.

Fig. i is a horizontal section takenon the line 4-4 of Figs. 2 or 3, looking from above.

Fig. 5 is a similar section taken on the line 5-5 of Figs. 2 or 3.

Fig. 6 is a top plan viewof a detail of the interior structure of the wall, and Figs. 7,

stantially the relative positions of certain elements including those shown in Fig. 6.

Fig. 10 is a vertical section through one of the key tiles 12 and surrounding parts.

' Fig. 11 is a view similar to Fig. 5 showing a removable or key tile and its relation to the wall front. I

Upon a suitable base or sill, composed for example of steel beams 11 is shown the hollow air cooled wall of this invention, the inner side or face of which is built up of a series of face tiles 12 having locking grooves 13 at their top and bottom edges, and engaging each other by offset or lap joints 14 at their ends as seen in Fig. 5. Beneath each course or tier of face tiles 12 is shown a tie-r of shallow tiles 15 which are formed with tongues or ribs 16 whereby these tiles are interlocked with the deeper face tiles 12. The locking tiles also may have lapping joints 17 as indicated in Fig. 4. For purposes to be more fully described some or all of the locking tiles 15 may be formed with integral outwardly extending lugs or knobs 18 at their rear surfaces, having enlarged heads and narrowed necks, and each forming the ball member of a sort of ball and socket connection or tie as will be described.

These face tiles 12 and 15 respectively are preferably composed of silicon carbide or other super-refractory, although as a matter of wall structure the disclosed construction is novel irrespective of the material. used, and indeed under some conditions the face elements of the wall might be constructed of fire clay refractories, or fused aluminum oxide, or any other suitable material.

Allowing for horizontal expansion the several. face tiles 12 and 15 may be slightly separated from each other and the vertical spaces packed with an elastic refractory packing 20. This packing may, for example, be asbestos cement or lagging. At the top of the series of face tiles there may be a relatively thick layer of flexible packing 21 between the topmost shallow tiles l5 and fixed cover tiles or bonding bricks or headers 22, which may be refractory, and set crosswise to interlock, with the outer or back elements of the wall. Thus a complete vwall section may beconstructed extending from the foundation up to the cover tile 22. In order to show however that the system of construction may be extended indefinitely there is indicated an additional and independent wall section above the cover tile 22. The cover tile 22 may have a lower groove 23 corresponding with the rib or tongue 16 of the shallow tile beneath it, and a tongue at its upper side for engagement with the lower groove of the deep tile 12 above- The cover tile 22 also may have an outward extension 25 interlocking with the body of the wall, andsome or all of the cover tiles 22 may have vertical air pamages 26, so that the cooling air may be and with a layer of thick packing material between the top cover tile and the shallow tile 15 beneath.

The outer portion of the disclosed wall may be composed of clay refractories or bricks 32 of relatively low grade but high strength. The mode of air travel through the-wall may vary considerably with the particular type of furnace and wall setting. For illustrative purposes air is shown entering at various points along the top of the upper wall sections and thence downwardly alon the outer surfaces of the facing tiles and t ence outwardly by suitable exit passages from which the air can be conducted beneath the grate if so desired, for combustion purposes. Thus an air inlet passage 33 is shown in the upper hind the facing of the wall. The air is thus distributed and brought into contact withthe back surface of the Wall facing near the top of the uppermost wall section, and from this point the air travels downwardly around the whole length of the wall, thus thoroughly scrubbing and extracting heat from the face tiles. The air when it reaches the bottom or the wall passes outwardly through a number of passages 37 leading into a continuous longitudinal chamber 38, from which at suitable intervals lead the air exit passages 39 as already mentioned.

The wall preferably contains a system of intermediate tiles or refractory elements 41 between the general air space 36 and the back wall or bricks 32. For this purpose occasional bricks 32 are set crosswise at intervals or prolonged inwardly so as to form a series of inward projections or shelves 40. These in turn give support to the intermediate elementsll which compose the intermediate portion of the wall, bounding the space 36.

part in this relation. The intermediate wall elements 41 are shown formed with projections or shelves 42 standing into the general air space 36. For example two of these may be side by side as seen in Fig. l and the combined shelf thus formed may be directly beneat-h the ball 18 of one of the face tiles. In this way every shallow face tile 15 is given direct support from the rigid intermediate wall elements. The ball or lug l8 normally rests on the shelf 42 but when compelled by expansion it may be lifted above the shelf. T he shelf members 42 are-preferably of short vertical dimension, so as to leave horizontal air passages 43 beneath them.

The described combination of elements is completed by the use of a number of tying elements 46 which may be constructed of cast irongcored out for lightness as indicated in Fig. 9, and each of which is in the nature of a socket or claw having a pair of fingers 47 which reach around and engage with the enlarged head or ball of the projecting lug 18 on the corresponding shallow face tile. Preferably, to protect the iron claw from overheating, the contact area between it and the ball is small in extent: in fact, as shown in Fig. 4, there is practically a single line contact 48, sui'licient to hold the parts in relation, but prevent excessive conduction of heat into the claw. ly on a refractory shelf 42, and the fingers engage around and interlock with the ball 18 as stated. The claw member 46 itself is secured and held bythe intermediate wall elements and in a manner to permit a swinging or swivelling motion horizontally. Due to this i'notion, and the ability of the ball to move vertically between the fingers of the claw member, complete flexibility of movement of every shallow face tile is assured, while at the same time the wall facing is held securely against buckling, bending or falling inwardly.

The mode of securing the iron claw member 46 in the rigid part of the wall is preferably such as to permit removal thereof without removal of the adjacent refractories. This may be arranged as follows. Each claw member 46 rests upon a shelf 42, while its outer extension is accommodated in a recess between two of the intermediate wall elements 41. The claw member may have upper and lower pivots 49 of a half round contour, these engaging in under and upper recesses Fill in the wall elements 41, so as to permit the side swinging motion referred to. iippcr and lower tracks or grooves 51 are shown provided at one or both sides of the pivot recess 50, leading diagonally from that recess. and adapted to permit the passage of the half round pivots 49 when the claw member is turned in the proper direction, as shown in Fig. 6. By this arrangement the claw member may be inserted into operative posi-l Each claw member 46 rests direct-' tion or removed therefrom by a simple sliding movement, and when in place and swung around to the dotted line position in Fig. 6 it is held securely against displacement, while free to undergo the rocking movement described.

Each flexibly mounted wall section may consist of four courses of deep face tiles 12 and four courses of locking tiles 15, although the number and arrangement could be varied, and the top of each section is closed and tied in by a course of bonding tiles or headers 22 set crosswise and extending into the wall backing. Each wall section moreover is divided vertically so that for example each ten inches of vertical construction is inder pendcntly supported. Thus every tile 12 rests upon a locking and supporting tile 15. The wall face thus self supporting, but without any tendency to buckle, slip or bulge.

For renewal purposes, see Fig. 10, one deep tile 12 in each course may be a key tile, shaped to hold its place in relation to the locking ribs of the tiles 15, yet so that with a slight effort the tile may be pried out and removed from the wall face. This may be done in view of the fact that the tiles above are themselves independently supported. Any damaged tile may thus be removed by extracting the key tile and sliding horizontally the tile to be removed, while in the same manner replacements can be inserted. The locking ribs may be omitted at the place of extraction and insertion. This can be done by chiseling off the ribs of the locking tiles at the position of the key tile. The key tile is shown slightly thicker than the other face tiles and formed with a short lower lug 19 extending slightly below the body of the tile, and an upper lug ll) of greater dimension. The key tile may be removed by prying it slightly up and drawing its lower part inwardly out of the wall. \Vhen removed the adjacent tiles may he slid into the same position and extracted. lVhc-n the removed tiles are replaced the key tile may be readily inserted,

and the slight space above the top edge of the key tile may be stuffed with refractory packing material 20. A special arrangement, as shown in Fig. 11,1nay be to construct each key tile 12* with symmetrical offset joints 14, namely with short horizontal extensions at the front or face. so as to facilitate insertion and removal. and with this arrangement the adjacent face tiles 12 can readily be accommodated by relatively inverting those at the left. of the key tile with respect to those at the right of it.

The wall. in one aspect may be described as follows. It comprises the face portion, relatively thin for rapid transfer of heat from the fire side, and the outer or back portion, the two spaced apart for the circulation of cooling air. Each wall portion is composed of refractory elements, blocks or bricks cut away or so shaped (see Figs. 2 and 3) as to permit substantial horizontal flow. The lugged elements or blocks comprise T-shape or ceutcr-lugged blocks (15, see Fig. 4) at alternate courses, for example in the wall face portion, and U-shape or end-lugged blocks (41, see Figs. 4 and 5), for example in the wall block portion, the lugs alining vertically as stated, in fact each lug 18 of a T-block alining vertically with a pair of adjacent lugs 120f two U-blocks, as appears in Figs. 1 and 4.

It will thus be seen that there has been described an air cooled furnace wall embodying the principles and attaining the advantages of the present invention. Since many matters of construction, operation, combination, arrangement, design and detail may be modified without departing from the principles of the invention it is not intended to limit the invention to such matters except so far as specified in the appended claims.

What is claimed is;

1. An air cooled furnace wall comprising a facing built up of refractory elements, and a backing spaced therefrom to leave interior air spacesoutward of the rear surfaces of the. face elements, said wall having air inlets and outlets arranged for air flow throughsaid spaces for scrubbing or cooling of the face elements, and interior means tying the facing to the backing at intervals while allowing movements of the face elements in the plane of the walls;- the face elements in each wall section being separated horizontally, lap jointed and packed, and interlocked vertically, with packing at the top of the wall section, and cover tiles above.

2. An air cooled furnace wall comprising a facing built up of refractory elements,and a backing spaced therefrom to leave interior air spaces along the rear surfaces of the face elements, said wall having air inlets and outlets arranged for air flow through said passages for cooling the face elements, and interior means tying the facing to the backing at intervals while allowing universal expansion movements of the face elements in the plane of the wall, said tying means comprising integralengaging extensions at the rear of some face elements, and complementary engaging devices on the wall backing; each engaging extension being in the nature of a' ball or knob formed at the rear of a. face tile, and each engaging device being in the nature of a socket or claw engaging the ball or knob, and the backing having projecting shelves upon which the several balls or knobs rest.

3. An air cooled furnace wall comprising a facing built up of refractory elements, and a backing spaced therefrom to leave interior air spaces, said wall having air inlets and outlets arranged for air flow through said passages for cooling the face elements, and interior means tying the facing to the backing at intervals while allowing movements of the face elements in the plane of the wall, consisting of a ball extension at the back of face tiles and a claw device engaging the hall, with a fixed refractory shelf supporting said ball andclaw.

4. A wall as in claim 3 and wherein the claw is arranged to swing horizontally on said shelf and the ball to slide up and down in the claw, whereby the face elements of the wall are universally movable in the plane of the wall. v

5. A wall as in claim 3--and wherein the claw device is detachably secured to the fixed refractory shelf.

6. An air cooled furnace wall comprising a facing built up of refractory elements, and a backing spaced therefrom to leave interior air spaces along the rear surfaces of the face elements, and interior means tying the facing to the backing at intervals while allowing movements of the face elements in the lane of the wall; said face elements arrange in a plurality of tiers each having means for supporting itindependently of the other tiers and said face elements comprising removable key tiles.

7. An air cooled furnace wall comprising a facing built up of refractory elements, and a backing spaced therefrom forming passages and with air inlets and outlets arran d for air flow through said passages for cooling the face elements, and interior means tying the facing to the backingat intervals while allowing movements of the face elements in the plane of the wall; the facing comprising periodic courses of lockin with the other face tiles, and having integral supporting lugs extending into such passages, and the wall backing having rejections into such passages on which said lugs rest and are supported.

8. An air cooled furnace wall comprising a facing built upof refractory elements, and

tiles, engaging cooling air behind at a relatively ra id rate,

and a wall back portion built up 0 refractory wall elements and spaced from the face portion to leave an internal wall space between them, for the forced circulation of cooling air, and an internal system of integral projections extending from wall elements into vsaid wall space, at least part of which abut a ainst the wall forming the opposite side 0 the space, the projections at successive tiers being in substantial vertical alinement to leave a series of substantially continuous vertical air circulationpassages behind the wall face portion, and the projections being shaped or cut away to permit horizontal-flow from each vertical passage to the next.

10. An air cooled furnace wall comprising I a wall face portion built up of refractory elements or tiles arranged in superposed tiers and relatively thin for rapid transmission of heat to the cooling air, and a wall back porticn built up of refractory wall elements and spaced from the face portion to leave an internal-wall space between them, one of said wall portions comprising wall elements having integral end projections extending across the wall space and abutting against the opposite wall portion for spacing apart the wall portions, and the wall face portion comprising wall elements having inte al middle projections superposed upon sai end projections, whereby vertical air circulation passages are formed between the several projections for the air scrubbing of the wall face portion.

'11. An air cooled furnace wall comprising a wall face portion built up of super-refractory wall elements or tiles arranged in superposed tiers and relatively thin for rapid transmission of heat to the cooling air, and a wall back portion built up of refractory wall elements and spaced from the face portime to leave an internal wall space between them, one of said wall portions comprising substantially U-shaped wall elements with its integral and projections extending across the wall space and abutting against the opposite wall portion for spacing apart the wall portions, and the wall face portion comprising substantially 'T-shaped wall elements with their integral middle projections extending into the space, each superposed in contact upon an adjacent pair of saidend projections.

12. A furnace wall as in claim 10 and wherein is a metallic tie piece secured in the well back portion and projecting into the wall space and subject to the cooling action of the air circulating therein and engaging loosely with a wall face portion projection.

13. A hollow furnace wall structure adapted to be cooled by forced circulation of air 7 through its interior space, the same having face and rear wall portions of refractory material, said face portion comprising superposed tiers of tiles made of highly refractory material, and having at alternate tiers a series of integral refractory projections extending into the wall space and shaped to leave vertical flow passages between them, and one of said wall portions having a series of refractory projections extending into the wall space between and in vertical alinement with said first mentioned series of projections to leave unobstructed such vertical passages and in contacting and supporting engagement with said first mentioned series, and one series of projections extending into abutting and spacing engagement with'the opposite side of the wall space. i

14. An air cooled furnace wall comprising a wall face portion exposed to the fire, built up of relatively thin super-refractory elements or tiles of high heat conductivity and of interlocking structure and arranged in' superposed courses and breaking vertical joints, and adapted to transmit heat through 06 the wall face portion to the cooling air be- .hind at a relatively rapid rate, and a wall back portion built up of refractory wall elements and spaced from the face portion to leave an internal wall space between them,

for the circulation of air, said wall having air inlet and outlet passages arranged. for

forced air travel distributed through said wall space for scrubbing and cooling the face elements, and an internal system of refractory projections extending integrally from we 1 elements into said wall spaces at each course, at least part of which projections extend into abutting contact with the wall forming maintain the spaced relation, and t e projections at successive courses being in substantial vertical alinement to leaverelatively large continuous vertical air circulation passages behind the wall face portion, but 116 so formed as to leave relatively small horizontal communicating passages 'rom each vertical passage to the adjacent ones.

15. A hollow furnace wall structure for air circulation, comprising an outer wall portion 120 and a facing portion spaced therefrom, the wall built up of lugged blocks of U-shape and .of T-shape respectively, assembled with their lu s extending into the hollow space within t e wall and with the lugs of the T- shape blocks in vertical alinement with the adjacent lugs of the U-shape blocks, to leave free vertical passages, the logs of at least one of such shapes extending across into abutting contact with the wall forming the op- 13 the opposite side of the s ace to 110 posite side of the space, to hold the wall portions apart, and a metal tie means cooperating with the lugs of one of such shapes to hold the wall portions from moving apart, said metal tie means being exposed to contact with the circulating air.

16. An air cooled furnace wall comprising a wall face portion exposed to the fire, built up of-refractory wall elements'arranged in superposed courses and adapted to transmit heat through the wall face portion to the cooling air behind at a relatively rapid rate, and a wall back portion built up of refractory wall elements and spaced from the face portion to leave an internal wall space between them, said wall having air inlet and outlet passages arranged for air travel through said wall space for scrubbing and coolin the face elements, an internal system of re actory projections extending integrally from wall elements into said wall space, the proj ections at successive courses being in substan tial vertical alinement and supporting contact to leave substantially continuous vertical air circulation passages behind the wall face portion, and some of said projections extending across into abutting and spacing contact with the opposite side of the wall space, and a system of metallic tie pieces secured in the wall back portion, extending into the wall space and subject to the cooling action of the air circulating therein, and detachably locking with projections of the wall face portion, to prevent the wall portions -moving apart.

In testimony whereof, I have aflixed my signature hereto.

- HENRY H. BAUMGARTNER. 

